Many prior art hypodermic syringes have a retractable needle. The needle is manually retrieved by the forward end of the plunger after a shot has been administered. The retraction of the plunger into the barrel pulls the needle into the body of the syringe. This manipulation of the hypodermic syringe requires both hands and it is possible that the hand holding the outer barrel could come in contact with the needle before it is fully retracted.
This invention relates to hypodermic syringes which have a barrel with a needle mounted on the forward end and a plunger inserted into the rear end. After the syringe has been used, the exposed needle is contaminated and must be disposed of in such a manner as to prevent inadvertent needles sticks. This invention automatically withdraws the contaminated needle into the syringe at the completion of the plunger stroke.